Working with Light Sources

Reference Number: KB-00777
Last Modified: January 7, 2020

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors


I know that I can use lighting to produce realistic 3D views of my work, but I'm not sure where to begin. Can you suggest some tips for working with light sources?
Outdoor scene with different lights


In Chief Architect, you can use light sources to help produce dramatic, photo-realistic 3D views of your model. To do so effectively though, takes an understanding of the different types of light sources available in the program, as well as a bit of practice.

There are two types of light sources in Chief Architect:

  • Point lights, which emit light equally in all directions.
  • Spot lights, which emit a cone of light in a particular direction only.

For most interior lighting needs, Point lights are recommended because they are the most similar to electric light bulbs. 

In addition to the two types of lights in the program, materials can be given emissivity, allowing surfaces to appear to glow with their own light. This property can be very effective when applied to a TV or projection screen.

To place lights

  • Select Build> Electrical> Light  from the menu, then click at a location where you would like to place an electrical light fixture.

    • If you click on a wall, a wall fixture will be created.

    • If you click away from a wall, a ceiling mounted fixture will be placed.

    • The default electrical objects that will be placed using this tool can be specified in the Electrical Defaults.

  • Navigate to Chief Architect Core Catalogs> Architectural> Lighting within the Library Browser and select an electrical light fixture.

    • When you move your cursor into the drawing area, it will display the Electrical  icon.

    • Click to place the selected library symbol in your plan. 

  • Select 3D> Lighting > Add Lights  from the menu, then click once to place a Spot light or click-and-drag to place a Point light without an associated 3D object.

    • Add Lights  allows you to customize the lighting in a space without adding electrical light fixtures.

    • This tool is only available in a 2D floor plan view.

To adjust lights

Once a light, or an electrical light fixture has been placed in your plan, it can be edited.

  1. Select 3D> Lighting> Adjust Lights from the menu to open the Adjust Lights dialog.

    • Alternatively, double-clicking on a light or an electrical light fixture within a floor plan or camera view will also open its specification dialog.

  2. Select the light or electrical light fixture that you want to modify and click on the Adjust button to open its specification dialog.

  3. In the Electrical Service or Light Specification dialog that opens:

    Light data panel of an electrical light fixture

    • On the General/Location panel, specify position and size properties for electrical light fixtures and display properties for lights.

    • On the Light Data panel:

      • Use the Light Source drop-down for electrical light fixtures that have more than one source. Click the Add Light or Delete Light buttons to add or delete light sources from an electrical light fixture.

        Electrical light fixtures that have 2 or more lightbulbs may have a separate light source that corresponds to each bulb. A track light with bulbs pointing in different directions is a great example where multiple light sources are used.

      • Adjust the Light Characteristics for each light source, such as the type of light (Spot or Point), intensity, color of light, as well as other properties.

        Selecting a distinct light color, such as red or blue, can help make changes to a lights settings more apparent in camera views.

      • Each light source can have its own unique settings and can be used in camera views, ray trace views, or both. Toggling the display of each source (On/Off), along with whether or not it casts shadows can also be specified.

    • Make any other desired adjustments and then click OK to close the dialog and apply your changes.

Lets now take look at how adjusting some of these values affect the light in a basic 20' x 30' structure.

Here is an example of a Bermuda Wall Mounted Sconce placed from the library. This electrical light fixture has 1 light source with a Point source type.

Notice how changing the light's Intensity value affects the 3D camera view.

Adjusting the Intesity of a sconce light fixture

Now, lets place a Recessed Down Light 4 light in the ceiling and specify it to use the Spot source type. Again, this fixture only has 1 light source specified.

As this is using the Spot source type, we have the ability to adjust additional characteristics such as Tilt, Direction, and Cut Off Angles, as well as the Drop Off Rate. A Tilt Angle with a value of -90° points the light straight down and a value of 90 points it straight up, while a Direction Angle of 0° points to the right horizontally in floor plan view. A value of 0° is parallel to the horizon. The Cut Off Angle defines the angle of the cone of light and can be between 0 and 180 degrees, while the Drop Off Rate describes the rate at which the light intensity within the cone of light decreases. When the Cut Off Angle is decreased, it's often a good idea to increase the Drop Off Rate.

For more information on these properties, click on the Help button while the light or electrical fixture is open to specification.

Lighting differences when tilt and direction angle are adjusted

Lighting differences when cut off angle and drop off rate are adjusted

Lets now experiment with a single electrical light fixture with multiple light sources that all use the Spot source type. Here, we will use the Basic 24 Track Light placed from the library. This electrical light fixture has 5 light sources by default, although for the purposes of this example, we will delete light sources 4 and 5. Notice, however, that light sources 1, 2, and 3 are only set to display light data for Ray Tracing. Go ahead and select the Use in Both option for all 3 light sources so we can see the different lighting effects in a standard 3D camera view. At this point, you can change the Tilt, Direction, and Cut Off Angle values to your liking, along with the Drop Off rate. Do keep in mind that the lighting heads that are part of the 3D Track Light symbol will not adjust with any changes that are made to the lighting characteristics.

Track light with 3 different light sources

When working with an electrical light fixture that has multiple light sources, you may want to check the Show Position in Camera View option for a given light source while in the specification dialog. This will display helpful markers while in a 3D Camera view. If the light source is a Spot light, a directional arrow will display as well.

Show position in camera view enabled for light source 3

Lastly, lets go ahead and modify lights that are placed without a 3D electrical light fixture associated with it. This is especially helpful if you're wanting to brighten a scene or add light to a particular area, but don't want to add an additional 3D symbol to the view. If you recall from the beginning of this article, it was mentioned that this can be done by navigating to 3D> Lighting> Add Lights and then either clicking to place a Point light or clicking-and-dragging to create a Spot light. If you notice that this tool is grayed out, you're likely in a 3D Camera or other unsupported view as this tool is only available in a 2D floor plan view.

Once a light is placed, you can open the light up to specification and modify the properties further. You may notice that multiple light sources cannot be added to a light such as this. If more light sources are needed, simply select the Add Lights tool once again and place as many lights as desired, each with their own properties. In the example below, you can see a floor plan view showing a single Point light aimed at a wall, a 3D Camera view showing the rendered results, along with the light characteristics that are used.

Spot light without an electrical fixture rendering light onto a wall

To manage lights

As a plan file becomes larger and more detailed, you will likely want to be able to manage or adjust properties of certain lights without much effort. This can be done by navigating 3D> Lighting> Adjust Lights . In the Adjust Lights dialog, you can see the properties of each electrical light fixture in a file, each added light, along with each light source. Lights and shadows can be turned ON/OFF, view options can be changed, and lights can be accessed and opened to specification if further modifications are needed.

For more information on the various properties in this dialog, click on the Help button.

Light properties displayed in the Adjust Lights dialog

To use an emissive material to simulate light

One of the advanced properties of a material is emissivity, which refers to its ability to emit light. This property can be used to create a realistic image such as for a television or projection screen.

  1. Use a digital image to create a custom material for display on a TV screen.

    For more information on creating a custom picture, see the Related Articles section below.

  2. Select 3D> Create Perspective View> Full Camera , then click and drag a camera towards the TV or projection screen.

  3. In the 3D view, use the Material Painter  tool to apply the custom material to the screen surface.

  4. Select 3D> Materials> Adjust Material Definition and click on the screen containing your custom image.

  5. On the Properties panel of the Define Material dialog, adjust the Emissive value to your liking.

    Adjusting the Emissive setting in the Define Material dialog

    • Emissive controls how bright a material appears independent of the lighting in the scene. It can be used to simulate surfaces that are glowing with their own light, such as the glass on a light fixture. This option is only available for General and Reflective materials.

  6. When the desired value is set, click OK to apply this change.